Hello. I'm trying to get microphone working with Realtek ALC892 on-board audio.
I have ASUS M4A89GTD Pro/USB3 motherboard.
I've selected "snd_hda_intel" module with "snd_hda_codec_realtek" codec. Audio works great. Also I can hear myself, when I'm talking to microphone.
When turning on/off microphone in Kmix and alsamixer - I can hear sound difference, so it looks like they are able at least mute/unmute mic.

it isn't all that straightforward configuring it just through alsamixer. In kmix i tick the box beneath 'capture', and all is well._________________Lost configuring your system?
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Had awful cracking sound with even the latest kernel (3.1.2 as of this writing) drivers and my ALC892 device. Removed the drivers from the kernel and installed alsa-driver-9999 which apparently has some fixes for this device.

An update to my previous post. With the installation of gentoo-sources-3.2.0-r1 I no longer need the external modules from alsa-driver-9999, the crackling is gone and the sound is fine with the kernel modules.

Basically only building the needed codec and not everything under HDA_INTEL - the other codecs are [=n]

Also using media-sound/alsa-headers-9999 and media-sound/alsa-tools-9999 plus motherboard is running the latest BIOS.

Maybe that info will help some. It is always possible that you have a hardware issue.

Note that at one point I needed to disable auto-mute for the Intel (Realtek) device in the alsa-mixer and although that doesn't seem to be the case currently I suggest you try that as well._________________A mouse is a device used to point at the xterm you want to type in.